1. Field of the Invention
The present invention relates generally to resistance devices for bicycle trainers, and more particularly to resistance devices that utilize a magnetic force to provide resistive forces.
2. Description of the Prior Art
Bicycle trainers have been known and utilized for many years. For instance, as disclosed in U.S. Pat. No. 4,768,782, entitled: Bicycle Exercising Apparatus, issued Sep. 6, 1988 to James R. Blackburn, a trainer is utilized to support a user's bicycle, typically the rear wheel, to provide a stationary exercise device. The rear wheel of the bicycle rotates upon a roller, and the trainer includes a resistance device that applies a resistive force to the rotation of the roller, thereby impeding the rotation of the rear wheel of the bicycle and providing exercise to the user. The trainer described in the '782 patent discloses a wind cage resistance device, however other types of resistance devices, specifically magnetic resistance devices are well known.
U.S. Pat. No. 4,826,150, reissued as reissue patent Re 34,479, entitled: Resistance Applying Means for Exercising Apparatus, reissued Dec. 14, 1993 to Chihiro Minoura, describes such a magnetic resistance device. In the '479 magnetic resistance device, a rotating disk is surrounded by two sets of permanent magnets. A fixed set of permanent magnets is positioned on one side of the rotating disk, and a movable set of permanent magnets is disposed on the other side of the rotating disk. Magnetic fields between the magnets on each side of the disk cause eddy currents within the rotating disk which inhibit the rotation of the disk. The magnetic forces are made adjustable by adjusting the location of the movable magnet set, relative to the fixed magnet set, such that the strength of the magnetic field between the magnets is altered. Alteration of the strength of the magnetic field creates an alteration in the magnetic resistance force.
The present invention includes a different orientation of magnets around a different rotating member, it includes a different way of applying the resistive force to the rotating member and a different way of adjusting the resistance force.